Magnetoelectronics devices, spin electronics devices and spintronics devices are synonymous terms for devices that use the effects predominantly caused by electron spin. Magnetoelectronics effects are used in numerous information devices, and provide non-volatile, reliable, radiation resistant, and high-density data storage and retrieval. The numerous magnetoelectronics information devices include, but are not limited to, magnetic random access memory (MRAM), magnetic sensors and read/write heads for disk drives.
Generally, a magnetoelectronics information device is constructed with an array of magnetoelectronics elements (e.g., giant magnetoresistance (GMR) elements or magnetic tunnel junction (MTJ) elements) formed in a substrate that may also include a variety of semiconductor devices, such as, for example, MOSFETs. The magnetoelectronics elements are programmed by the magnetic field created from a current-carrying conductor. Typically, two current-carrying conductors, one formed underneath the magnetoelectronics element and one formed on top of the magnetoelectronics element, are arranged in cross point matrix to provide magnetic fields for programming of the magnetoelectronics element.
Advanced semiconductor processes often use copper metal interconnects for the current-carrying conductors. The preferred method of forming the top copper metal interconnect is by a damascene or inlaid process during which a trench is patterned and etched in a dielectric layer, followed by the deposition of a copper layer within the trench. Any excess copper is removed, typically by chemical mechanical planarization (CMP). After formation of the copper metal interconnect, the surrounding dielectric layer may be removed to allow for deposition of a cladding layer over the interconnect. Cladding layers are used to focus the magnetic flux of the interconnect to the magnetoelectronics element.
One method used to remove the dielectric layer is dry plasma etching. However, the copper metal interconnect and semiconductor devices in the substrate may accumulate charge from the plasma which may create an over voltage or over current condition that is damaging to the semiconductor devices. For example, if a semiconductor device is a MOSFET and the copper metal interconnect is electrically coupled to the gate, source or drain of the MOSFET, the plasma-induced charge may inject hot carriers into the gate oxide, thus causing a shift in device performance.
Accordingly, it is desirable to provide an improved method for fabricating a cladded conductor for use in a magnetoelectronics device. It is also desirable to provide a cladded conductor that does not adversely affect devices electrically coupled thereto. Other desirable features and characteristics of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings.